PUBLIC LAW 100-647—NOV. 10, 1988 102 STAT. 3765 ' section 10(d), during the 4 calendar quarters ending on that June 30. . "(B) STEP 2.—Add the aggregate amount of any additions to the system unallocated charge balance specified in para- graphs (15) and (16), during that period. "(C) STEP 3.—Add the aggregate amount of any other expenditures by the account during that period not charge- able to any individual employer under paragraph (15) or to the fund under section 11. "(D) STEP 4.—Subtract the aggregate amount of ^all income to the account, under section 10(aXiv) or section KXaXvii), during that period. "(E) STEP 5.~-Subtract the aggregate amount of all trans- fers to the account, pursuant to section ll(d), during that period. "(F) STEP 6.—Subtract the aggregate amount of all other income and receipts of the account, during that period, which are not assigned to individual employer balances. "(G) STEP 7.—-Subtract the net cumulative contribution balance of each employer whose balance has been cancelled pursuant to paragraph (16), during that period, calculated as of the date of such cancellation. "(11) SYSTEM COMPENSATION BASE.—The system compensation base as of any given June 30 shall be determined by adding together the amounts of the 1-year compensation bases of all employers and employee representatives subject to this Act, computed in accordance with paragraph (5), as of such June 30. "(12) POOLED CREDIT RATIO.—The pooled credit ratio, if any, for a calendar year shall be determined as follows: "(A) STEP l.—Compute the balance to the credit of the account as of the close of business on the preceding June 30, including any amounts in the account attributable to loans made under section 10(d) before October 1, 1985, but dis- regarding the obligation to repay such loans and interest thereon. In determining such balance as of June 30 of any year, so much of the balance to the credit of the railroad unemployment insurance administration fund as of the close of business on such date as is in excess of $6,000,000 shall be deemed to be part of the balance to the credit of such account. There will be a pooled credit ratio for the calendar year only if that balance is in excess of the greater of $250,000,000 or of the amount that bears the same ratio to $250,000,000 as the system compensation base as of that June 30 bears to the system compensation base as of June 30, 1991, as computed in accordance with para- graph (11). "(B) STEP 2.—If there is such an excess amount, divide that excess amount by the system compensation base as of the June 30 preceding the calendar year. The result is the pooled credit ratio for the calendar year. "(13) POOLED CHARGE RATIO.—-The pooled charge ratio, if any, for a calendar year shall be determined as follows: "(A) STEP i.—With respect to each employer whose con- tribution rate for that calendar year as computed through step 6 under paragraph (IXC) was greater than the maxi- mum contribution limit computed under paragraph (20), multiply the employer's 1-year compensation base as of the